Biodegradation potential of indigenous litter dwelling ligninolytic fungi on agricultural wastes

Background The present study was focused to study the efficiency of two indigenous litter dwelling ligninolytic fungi (such as Mucor circinelloides GL1 and Fusarium verticillioides GL5) in degrading the agricultural wastes (areca husk, coffee husk and paddy straw) through solid-state fermentation. Results After fermentation process, the lignocellulosic residues left over were evaluated for their physico-chemical studies and degradation pattern of cell wall constituents along with the activity of enzymes. In each substrate, the initial pH was found to change from near-neutral to acidic pH after fungal decomposition. Significantly increased loss of total organic matter and organic carbon content was observed in each substrate decomposed by the fungal strains selected. The total nitrogen, crude protein, total phosphorus and total potassium contents of the fungal decomposed substrates were significantly increased with the progress of time. The study indicated that the degradation patterns of lignin and holocellulose were more effective from 20 to 120 days after fungal inoculation with respect to their loss between the different harvesting intervals. During decomposition process, both the strains produced the ligninolytic enzymes [laccase, manganese peroxidase (MnP) and lignin peroxidase (LiP)] and carboxymethyl cellulase (CMCase) on each substrate with their remarkably varied activities with respect to different harvesting times. Conclusions In concern with the present environmental problems, the present study suggested that these potential ligninolytic fungi can be utilized successfully for the management of agricultural wastes and reuse of their residues in the forest soil conservation system to eliminate the harmful effects of the crop residue burning.